Toner replenisher device

ABSTRACT

A toner replenisher unit for an electrostatic copying device. The toner particles are abraded off a solid toner block. Constant pressure is maintained between the toner block and the abrading roll throughout the consumption of the toner block by a spring acting through a ratio pulley, such that the spring force reduces as the weight of the toner block is reduced. Loading of the abrading roll is prevented by a brush which removes any toner particles. Toner particles, which do not freely fall from the brush, are removed by a brush wiper. Means are provided for accepting and positioning the toner block with an attached pallet so that the upper surface of the pallet is substantially parallel to a chord described by the edges of the surface ground into the toner block by the abrading roll.

United States Patent Primary Examiner- Donald G. Kelly Atwrneys- Hanifinand Jancin and Maurice H. Klitzman ABSTRACT: A toner replenisher unitfor an electrostatic copying device. The toner'particles are abraded offa solid toner block. Constant pressure is maintained between the tonerblock and the abrading roll throughout the consumption of the tonerblock by a spring acting through a ratio pulley, such that the springforce reduces as the weight of the toner block is reduced. Loading ofthe abrading roll is prevented by a brush which removes any tonerparticles. Toner particles, which do not freely fall from the brush, areremoved by a brush wiper Means are provided for accepting andpositioning the toner block with an attached pallet so that the uppersurface of the pallet is substantially parallel to a chord described bythe edges of the surface ground into the toner block by the abradingroll.

PATENTEDunv 9 l97l SHEET 1 BF 2 INVENTORS RICHARD A. BERLIER DYER T.MCCRORY TONER REPLENISHER DEVICE BACKGROUND OF THE INVENTION 1. Field ofthe Invention The invention relates to electrophotographic chemistry,process and materials, and more particularly, apparatus for producingdocument copies.

2. Description of the Prior Art The process of electrostatic copyinginvolves evenly coating a plate formed of a photoconductive insulatingmaterial with electrostatic charges. The photoconductive insulatingmaterial is then exposed to the subject matter to be reproduced by aconventional imaging technique. This exposure discharges theelectrostatic voltage on the plate in proportion to the amount ofradiation striking any particular portion of the plate. After theexposure there remains on the plate electrostatic charges forming alatent image of the subject matter imaged onto the plate.

The latent image is developed by cascading over the plate a chargedfinely divided dark-colored thermoplastic powder, hereinafter referredto as toner. Generally, before the toner is cascaded over the exposedphotoconductive insulating plate, the toner is combined with a granularcarrier material. This material more evenly distributes theelectrostatic charge among the toner particles and provides for easiertransport of the toner particles to and over the electrostatic plate.

After the latent image has been developed by the toner particles, theimage, in the form of the toner particles, is transferred to a sheet ofpaper. The toner particles are then fixed" to the paper by a fusingelement. It is seen that as the process continues, toner particles areconsumed and must be replaced.

in most prior art devices the replenishing toner is provided in powderedform. This toner is placed into a compartment from which it is removedin carefully metered quantity to be combined with the granular carrierparticles. Not only is it difficult for an operator to load thecompartment with the toner, but it is inherently messy. The fineparticles of toner form a black cloud when being poured into thecompartment and, more often than not, soil both the electrostaticcopying device and the operator.

Further, metering the correct quantities of toner particles from thestorage compartment is a complicated and exacting task. Prior artdevices have gone to great lengths to insure that the correct amount oftoner particles are metered. If too many particles are metered, theeventual image will be too dark and contain the fused black tonerparticles in undesired locations. If too little is metered, the fulllatent electrostatic image will not be developed.

in order to overcome these objections a few prior art devices have usedtoner in block form. These toner blocks are usually prepared by mixingthe original finely divided powder with well-known bonding agents andthen subjecting the material to pressure. There are other well-knownmethods of forming such toner blocks.

The prior art devices using toner blocks, rather than metering tonerfrom the compartment in which it is stored, remove the toner particlesfrom the blocks in the desired amounts, usually by abrasive techniques.However, these latter prior art devices suffered from numerous faults.First, many were not adjustable. That is, the operator of theelectrostatic device could not adjust the quantity of toner particles tobe removed from the toner block.

Other devices were adjustable, but in adding this feature so complicatedthe mechanism for removing the toner particles, as to make the devicecommercially unfeasible.

Further, whether adjustable or not, the prior art devices, as the tonerblock was consumed, removed varied amounts of toner. That is, the amountof toner removed from the toner block is proportional to the force withwhich the toner block presses against the removing member (generally anabrading roll). Most prior art devices use spring pressure to maintainthis force between the toner block and the abrading roll. As is wellknown to those skilled in the art the force exerted by a spring isproportional to its extension. Thus, as the block was consumed, thesprings extension changed and so did its force. With this change in theforce exerted by the spring there was a proportional change in the forcebetween the toner block and the abrading roll. The net result was aconstantly varying amount of toner production.

Prior art devices using toner blocks encountered vibrations and chatterwhen the grinding roll removed the toner. This damages and chips theblock and effects the toner replenishing rate.

Also, the prior art devices using toner blocks did not containconvenient loading mechanisms. Generally, the toner block had to becarefully mounted ontothe mechanism which urged it into contact with theabrading means. This necessitated that the operator acquire skill inloading the electrostatic copying device. Further, it was atime-consuming operation.

Other prior art devices had difficulty, after removing the tonerparticles from the toner block, in making them available for developingthe latent image. For example, often the toner particles would lodge inthe abrading roll; thereby clogging the abrading roll removing thoseparticles from further use and, in some cases, causing a deteriorationof the abrading function.

Therefore, it is an object of this invention to provide an improvedtoner replenisher unit which does not necessitate powdered toner.

It is another object of this invention to provide an improved tonerreplenisher unit which utilizes toner in a compressed block fonn.

it is another object of the invention to provide force means forremoving a constant amount of toner from the toner block,notwithstanding the amount of toner that has already been removed.

it is another object of the invention to provide such force means in aneconomical and easily fabricated mechanism.

It is another object of the invention to provide means compatible withmaintaining a constant pressure for removing toner particles from atoner block in adjustable quantities.

it is another object of the'invention to reduce chatter while removingparticles from the toner block.

it is another object of this invention to provide means for easilyloading the toner block.

Lastly, it is an object of this invention to completely remove allparticles from the abrading means so that they can be utilized indeveloping the latent image.

SUMMARY OF THE INVENTION in accordance with the above objects, thepresent invention provides a spring or equivalent (such as pneumatic orhydraulic means) exerting a mechanical force to urge the toner block tocontact the grinding (abrading) rolls with a constant pressure. Thispower supply comprises a spring held in tension. The amount of extensionof this spring is adjustable by a selflocking worm and gear arrangementthrough a cable takeup pulley. Because of the cable takeup pulley, alarge turn of the worm gear by the cranking handle, causes a smallchange in the pressure between the toner block and the grinding roll.The spring exerts its pressure on the toner block through a ratiopulley. The ratio pulley prevents large changes in the extension of thespring; thereby, insuring that the force of the block against theabrading rolls is substantially constant.

The invention provides for easy loading of the toner block by allowingthe placement of the toner block in its storage compartment with anattached pallet. The operator has only to slip the adapting slot on thepallet onto a shaft provided in the toner block compartment. Further,when the front wall of the compartment is closed, an additional pressureis placed upon the block forcing it into correct engagement with thegrinding roll.

When the pallet has assumed its correct position in the toner blockcompartment, the upper surface of the pallet is substantially parallelto the surface ground into the toner block by the grinding roll. Thisallows the grinding roll to remove all the possible toner from thepallet.

A brush removes the particles embedded in the grinding roll makingavailable for development all toner particles removed from the tonerblock and preventing the clogging of the grinding roll. Further, anyparticles that might have lodged in the brush, are removed by a brushwiper.

Thus, the invention meets all the above objects with an uncomplicated,easily fabricated, and economically feasible toner replenisher unit.

BRIEF DESCRIPTION OF THE. DRAWINGS The foregoing and other objects,features and advantages of the invention will be apparent from thefollowing more particular description of the preferred embodiment of theinvention as illustrated in the accompanying drawings.

FIG. 1 is a diagrammatical representation of the preferred embodiment ofthe invention.

FIG. 2 is a side view of the grinding roll and toner bloclt supportmechanism.

DETAILED DESCRIPTION OF THE DRAWINGS In order to control the force withwhich toner block 43 is urged against grinding roll 45, a control meansis provided. Referring to FIG. I the control means is seen to comprise acranking handle ll onto which is mounted a worm gear 3. Worm gear 3engages gear 5. Worm gear 3 and gear 5 form the well-known self-lockingworm gear assembly. Gear 5, indicator wheel 9, and cable takeup pulleyII are affixed to indicator shaft 7. Permanently amxed to thecircumference of cable takeup pulley II is one end of cable 113. Theother end of cable 13 is connected to power spring l5 after contactingpulley 17. The other end of power spring I5 is attached to pin 19. Pin19 is permanently affixed to lever Ell. Also connected to pin 19 iscable 23. Cable 23 winds around pulley 25 and is attached to hub 27 onratio pulley 29.

The power means of the invention is thus composed of devices indicatedby reference numbers lid-29. Ratio pulley 29 prevents large movements inpower spring and thus, acts in the maintenance of a constant pressurebetween toner block 43 and grinding roll 45.

Permanently attached to the large circumference of ration pulley 29 isthe linkage means composed of cables 31 and 33. Cable 31 contacts pulley35 before its other end is attached to one end of shaft 39; cable 33contacts pulley 37 before its other end is attached to the other end ofshaft 39. Shaft 39 supports easily removable pallet dll onto which ispermanently attached toner block 483. Under the urging of power spring15 and connecting cables 23, 31 and 33, toner block 43 is forced intocontact with grinding roll 45.

In order to utilize all the toner present in the toner block 43 a brush47 is in contact with grinding roll 45; and in contact with brush 47 isbrush wiper d9. It is seen that grinding roll l5 in the preferredembodiment is composed of many sharp toothlike projections around itscircumference, much in the nature of a ratchet. Brush d7 wipes grindingroll 45 cleaning any accumulation of toner particles that have lodged ingrinding roll 45. In turn brush wiper 39 cleans the accumulatedparticles from brush 47. Thus, there are substantially no tonerparticles left in grinding roll or brush 47. Since no particles arelost, this also maintains a constant quantity of toner production.

Lever 21 rotates on pin 5i. Lever 21 can be rotated from the normalposition as shown in FIG. I to a position so that its trailing edgeengages extension 53 on latch 55. When lever 21 so engages latch 55tension is removed from cable 23 allowing shaft 39 to lower under itsown weight. The pallet of the used toner block 43 can then be removedfrom shaft 359 and a new toner block and attached pallet can beinserted.

Referring now to FIG. 2 a side view of the lower portion of FIG. 1 isshown. In addition to the structure shown in FIG. 11, FIG. 2 shows thecompartment or housing in which pallet 41 and toner block 4131 move.This housing is composed of sidewalls 557, back wall 59, and front wallat. Sidewalls 57 each have a guide 63 in which shaft 39 travels. Frontwall 61 is pivotably mounted onto sidewalls 57 by screws 65. When frontwall an is opened, pallet All and the attached toner block 33 can bemounted upon exposed shaft 39. As can be best seen from FIG. 2, pallet41 mounts onto shaft 39 by merely slipping pallet dll onto shaft 39.Shaft 39 engages a slot 40 in pallet 41.

Also shown in FIG. 2 is a spring 67 attached to wall 69 (wall 69 is apart of the rest of case enclosing the entire copier). Spring 67positively engages the upper portion of toner block 43 forcing tonerbloclt 43 toward rear wall 59. Spring 67 is ad ditionally forced againsttoner block 43 under the urging of front wall till. Rear wall 59 mayhave supporting strips attached thereto preferably composed of alow-friction coefficient material such as nylon or Teflon. Attached tothe lower portion of wall 59 is a deflector plate 71. Deflector plate 71deflects the toner particles ground from toner block 43 into a sump, notshown, for accumulating both the toner material and carrier particles.

It has been found that if the toner block is set slightly off of thecenterline of the grinding roll, chatter and chipping of the toner blockis minimized. That is, by positioning the toner bloclt so that thegrinding roll preferably grinds the toner block, at an anglesubstantially as shown, chatter and chipping of the toner block isreduced. This minimizes the tendency to chip the exit edge of block 43as the teeth of roll 45 move out of contact with the top surfaces ofblock 43. This can best be seen in FIG. 2.

This is in contrast to the ordinary situation where the center of thetoner block is an extension of a radius of the grinding roll. In theordinary situation half of the grinding roll in contact with the tonerblock grinds down into the toner block and the other half of thegrinding roll grinds up and out of the toner block.

However, when the toner block is offset from a radius of the grindingroll, the grinding roll is enabled to remove almost all of the tonerblock from the pallet. This is possible because the surface plane of thepallet is parallel to a chordal plane formed by the connections of edges42 and 44 of the toner block 43 in FIG. 2.

Also seen in FIG. 2 is the relationship described above between grindingroll d5, brush 417, and brush wiper l9.

OPERATION OF Tit-IE INVENTION Cranlting handle ll is turned dependingupon the amount of toner particles desired. That is, turning crankinghandle I increases or decreases the tension in power spring 15 throughworm 3, gear 5, shaft 7, cable talteup pulley II, and cable 13. Throughcable 23, ratio pulley 29, cables 31 and 33, and shaft 39 pallet di andtoner block d3 are urged into contact with grinding roll 45'. Thegreater the tension present in power spring 15, the greater the forcewith which toner block 43 is urged against grinding roll did. The morepressure between toner bloclt 413 and grinding roll 45, the more tonerparticles grinding roll 45 removes from toner block 43.

Indicator wheel 9 has numeric indications representative of a range offorce exerted by power spring 15, and thus, indirectly indicates theamount of toner particles removed from toner bloclt 4335. As an example,a setting of 0 may produce minimum toner replenishing while a setting of5" may produce maximum replenishing.

The foregoing arrangements permit the selection of any of a number ofdesired grinding (consumption) rates. Within a predetermined range whilemaintaining the speed of the grinding roll constant.

The particles ground off toner block 43 either fall from grinding roll45' or are removed from grinding roll 45 by brush 47. The particles thatdo not freely fall from brush 47 are removed by brush wiper 49. All theparticles fall into the toner and carrier sump (not shown) eitherdirectly or after being deflected by deflector plate 71.

To load a toner block 43 with the attached pallet 41, lever 2! isrotated to the right so that its trailing edge engages extension 53 onlatch 55. This removes the tension from cable 23, allowing shaft 39 tofall under its own weight. Front door 61 is pivoted downwardly, exposingthe interior of the compartment in which pallet 41 travels. The depletedtoner block 43 with its pallet 41 is removed, and a new toner block 43with its attached pallet 41 is inserted onto shaft 39. Front wall 61 ispivoted upwardly enclosing the compartment and additionally urgingspring 67 against the toner block causing the toner block to restagainst rear wall 59. The angle to the horizontal which pallet 41assumes permits grinding roll 45 to almost completely remove all tonermaterial mounted upon pallet 41.

As the toner block 43 is consumed, its weight decreases and springshortens due to the shortening of the block 43. The spring forcedecreases with any decrease in its deformation and if the system isproperly dimensioned the net changes in weight and spring force offseteach other. This yields a net force exerted by the abrading roll 45 onthe toner block 43 that remains substantially constant. This net forcewill be proportional to the force required to extend the spring 15 to aposition such that the ends of cables 31 and 33 are at their uppermostpoint of travel.

The proportionality of the force of the roll 45 against the block 43 isdetermined by the relation of the radius of hub 27 to the radius of thelarge hub of ratio pulley 29. Any change in pressure between roll 45 andblock 43 is directly effected by the dividing effect of the ratio pulley29 on the force exerted by spring 15 for any change of setting ofindicator wheel 9.

One skilled in the art will see from the above description and thedrawings that there will be an insignificant pressure change between theblock and the grinding roll over the distance while pallet 41 moves forany selected guide number on the indicator wheel 9. This tension inpower spring 15 results in a constant pressure being applied betweengrinding roll 45 and toner block 43. Therefore, this aspect of theinvention allows a constant pressure to be applied between toner block43 and grinder roll 45 throughout the entire movement of pallet 41 andconsumption of toner block 43 without necessitating a resetting ofcranking handle 1.

As block 43 is consumed its weight decreases in a linear fashion, thelength of spring 15 decreases thereby decreasing the force it exerts,and the arrangements just described therefore provide an automaticcompensation to insure that a constant pressure between block 43 androll 45 is substantially maintained throughout. the consumption process.

Lastly, because of brush 47, brush wiper 49, and deflector 71, it isseen that all toner particles are forced to fall into toner anddeveloper sump (not shown). Through proper dimensioning of the apparatusparticles can be prevented from falling back into the compartment inwhich is located toner block 43. This not only allows all tonerparticles to be used for developing the latent image, but also maintainsthe clean lines of the toner storage compartment. The latter advantageallows an operator to change the toner block without fear of soilinghimself.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention.

We claim:

1. A toner replenisher unit providing particles from a solid toner blockincluding:

force means for supplying a stable mechanical force including a springand a ratio pulley comprising an inner hub and a large outer hub, thesaid inner hub connected to said spring and said outer hub connected toa linkage;

control means for variably setting the force supplied by said forcemeans;

grinding means for removing particles from said toner block;

said linkage connected to said force means for forcing said toner blockagainst said grinding means with a constant pressure.

2. A toner replenisher unit providing particles from a solid toner blockcomprising:

a spring;

control means for varying the extension of said spring;

a ratio pulley comprising an inner hub and an outer hub, the

inner hub connected to said spring;

linkage means for urging a toner block into contact with a grindingmeans for removing particles from said solid toner block, and saidlinkage means connected to the outer hub of said ratio pulleymaintaining a constant force between said toner block and said grindingmeans.

3. A device as in claim 1 including power release means for extendingsaid spring to its fullest extension causing said linkage means to movesaid toner block away from said grinding means.

4. A device as in claim 3 wherein said linkage means includes a shaftfor supporting a removable toner block with an attached pallet.

5. A device as in claim 4 wherein said grinding means grindssubstantially down into said block so that the upper surface of saidpallet is substantially parallel to the chordal plane of the surfaceground into said toner block by said grinding means.

6. A device as in claim 4 including:

brush means for removing the particles from said grinding means; and

brush wiper means for removing the toner particles from said brushmeans.

7. A device as in claim 1 wherein said control means includes:

handle means;

a self-locking worm and gear means connected to and controlled by saidhandle means;

a shaft on which said gear means is mounted;

indicating means mounted on said shaft;

cable takeup means mounted on said shaft; and

a cable connected to the periphery of said cable takeup means and tosaid spring means for controlling the extension of said spring meansaccording to the movement of said handle means.

8. A toner replenisher unit providing particles from a solid toner blockincluding:

grinding means for removing particles from said solid toner block;

brush means for removing the means; and

brush wiper means for removing the toner particles from said brush meansand deflecting the toner particles away from the toner block.

9. A device as in claim 2 wherein the means included in said linkagemeans is a shaft which supports a pallet, said means supporting saidpallet and toner block with said grinding means grinding substantiallydown into said toner block so that said pallets upper surface issubstantially parallel to the surface ground into said toner block bysaid grinding means.

particles from said grinding

1. A toner replenisher unit providing particles from a solid toner blockincluding: force means for supplying a stable mechanical force includinga spring and a ratio pulley comprising an inner hub and a large outerhub, the said inner hub connected to said spring and said outer hubconnected to a linkage; control means for variably setting the forcesupplied by said force means; grinding means for removing particles fromsaid toner block; said linkage connected to said force means for forcingsaid toner block against said grinding means with a constant pressure.2. A toner replenisher unit providing particles from a solid toner blockcomprising: a spring; control means for varying the extension of saidspring; a ratio pulley comprising an inner hub and an outer hub, theinner hub connected to said spring; linkage means for urging a tonerblock into contact with a grinding means for removing particles fromsaid solid toner block, and said linkage means connected to the outerhub of said ratio pulley maintaining a constant force between said tonerblock and said grinding means.
 3. A device as in claim 1 including powerrelease means for extending said spring to its fullest extension causingsaid linkage means to move said toner block away from said grindingmeans.
 4. A device as in claim 3 wherein said linkage means includes ashaft for supporting a removable toner block with an attached pallet. 5.A device as in claim 4 wherein said grinding means grinds substantiallydown into said block so that the upper surface of said pallet issubstantially parallel to the chordal plane of the surface ground intosaid toner block by said grinding means.
 6. A device as in claim 4including: brush means for removing the particles from said grindingmeans; and brush wiper means for removing the toner particles from saidbrush means.
 7. A device as in claim 1 wherein said control meansincludes: handle means; a self-locking worm and gear means connected toand controlled by said handle means; a shaft on which said gear means ismounted; indicating means mounted on said shaft; cable takeup meansmounted on said shaft; and a cable connected to the periphery of saidcable takeup means and to said spring means for controlling theextension of said spring means according to the movement of said handlemeans.
 8. A toner replenisher unit providing particles from a solidtoner block including: grinding means for removing particles from saidsolid toner block; brush means for removing the particles from saidgrinding means; and brush wiper means for removing the toner particlesfrom said brush means and deflecting the toner particles away from thetoner block.
 9. A device as in claim 2 wherein the means included insaid linkage means is a shaft which supports a pallet, said meanssupporting said pallet and toner block with said grinding means grindingsubstantially down into said toner block so that said pallets uppersurface is substantially parallel to the surface ground into said tonerblock by said grinding means.